Photoanode Development Through Combinatorial Integration of mixed-metal Oxide Catalysts on Bismuth vanadate

Guevarra, D. et al. Development of solar fuels photoanodes through combinatorial integration of Ni–La–Co–Ce oxide catalysts on BiVO4. Energy & Environmental Science, DOI: 10.1039/C5EE03488D (2015).


Scientific Achievement

Multi-metal compositions of (Ni-La-Co-Ce)Ox oxygen evolution reaction (OER) catalyst coatings improve the photoelectrochemical power conversion efficiency 20-fold compared to bare photoanode material, such as bismuth vanadate(BiVO4).

 

Significance & impact

This study shows that high-throughput characterization can enable identification of metal oxide compositions whose performance in integrated photoanodes greatly exceeds predictions, indicating improved interfaces.

Research Details


  • Discrete (Ni-La-Co-Ce)Ox coatings were synthesized on a uniform BiVO4 thin film yielding 858 catalyst/BiVO4 assemblies with 3 different catalyst loadings.
  • Catalysts that enhance pH 13 OER activity were identified via high-throughput photoelectrochemical screening and verified by traditional characterization of scaled-up La0.2Co0.2Ce0.6Ox/BiVO4 photoelectrodes.
  • Compositions exceeding predicted performance, suggesting improved interfaces, are shown in yellow. Compositions that were underperforming are shown in purple, suggesting presence of degraded interfaces.

Contact: fmtoma@lbl.gov; gregoire@caltech.edu; jahaber@caltech.edu

  Adapted fromGuevarra, D. et al. Development of solar fuels photoanodes through combinatorial integration of Ni–La–Co–Ce oxide catalysts on BiVO4. Energy & Environmental Science, DOI: 10.1039/C5EE03488D (2015)with permission of The Royal Society of Chemistry. Experimentally measured (a) transparency and (b)  performance of catalysts on fluorine doped tin oxide (FTO). (c) Predicted performance (αC,cat) of catalysts on BiVO4 obtained by combining results from (a) and (b) measurements. (d) Measured performance (Pmax) of an integrated photoanode (i.e., catalyst mapped onto BiVO4) that shows differences between the observed and predicted results. (e) Parameter Γ compares photoanode performance (Pmax) to that predicted by αC,cat. Areas in yellow are approximately 10-fold better performing than anticipated, suggesting that well-controlled interface engineering is critical to performance of integrated catalyst-light absorber assemblies.

 

Adapted fromGuevarra, D. et al. Development of solar fuels photoanodes through combinatorial integration of Ni–La–Co–Ce oxide catalysts on BiVO4. Energy & Environmental Science, DOI: 10.1039/C5EE03488D (2015)with permission of The Royal Society of Chemistry.

Experimentally measured (a) transparency and (b)  performance of catalysts on fluorine doped tin oxide (FTO). (c) Predicted performance (αC,cat) of catalysts on BiVO4 obtained by combining results from (a) and (b) measurements. (d) Measured performance (Pmax) of an integrated photoanode (i.e., catalyst mapped onto BiVO4) that shows differences between the observed and predicted results. (e) Parameter Γ compares photoanode performance (Pmax) to that predicted by αC,cat. Areas in yellow are approximately 10-fold better performing than anticipated, suggesting that well-controlled interface engineering is critical to performance of integrated catalyst-light absorber assemblies.